The invention relates to medicaments favouring the properties of blood flow and to their use in therapeutics.
This invention constitutes a development of that described in U.S. patent application Ser. No. 204,505 of Nov. 5, 1979, which issued on Sept. 8, 1987 as U.S. Pat. No. 4,692,435, in which medicaments are described containing mucopolysaccharide fractions endowed with biological properties enabling them to play a regulating role with respect to blood clotting, more particularly in the sense of retarding coagulation. This regulatory action is exerted by the bringing into play of inhibitory actions more selective than those of heparin, with respect to a smaller number of factors of coagulation, more particularly of the activated X factor (factor Xa).
These mucopolysaccharides can be obtained by alcoholic fractionation from heparin or from fractions including heparinic constituents as recovered by extraction from animal tissues or organs, in particular of mammals (it will be noted that the term "heparin" is used to denote indifferently a commercial heparin of pharmaceutical grade or a heparin obtained by extraction).
According to their broadest definition, the fractions according to the said US application, are characterised particularly by the following properties
they possess a molecular weight of about 2000 to 10,000 daltons;
they are soluble in an aqueous alcohol medium (water-ethanol) having a titer of 55.degree.-61.degree. GL;
they tend to insolubility in a water-alcohol medium having a higher alcohol content;
they are insoluble in pure alcohol;
they possess a ratio of the anti-Xa titer (measured by the Yin-Wessler titer) to the USP titer, of at least 2, particularly at least 3, and even higher than 6.
The inventors have now observed that these fractions exert a powerful action on the rheological behaviour of the blood.
Investigations based on these results have enabled such an action to be demonstrated, generally, in other mucopolysaccharide fractions and compositions corresponding to the above general characteristics.
In the description which follows, these products will also be denoted by the term oligosaccharide.
It is therefore an object of the invention to provide novel medicaments enabling the blood flow to be favoured to an important degree. It is also an object to provide for their use in different administrative forms to counter the factors responsible for blood hyperviscosity.